An Efficient Certificate-Based Aggregate Signature Scheme for Internet of Drones

Internet of drones (IoD) is a network of small drones that leverages IoT infrastructure to deliver real-time data communication services to users. On the one hand, IoD is an excellent choice for a number of military and civilian applications owing to key characteristics like agility, low cost, and ease of deployment; on the other hand, small drones are rarely designed with security and privacy concerns in mind. Intruders can exploit this vulnerability to compromise the security and privacy of IoD networks and harm the information exchange operation. An aggregate signature scheme is the best solution for resolving security and privacy concerns since multiple drones are connected in IoD networks to gather data from a certain zone. However, most aggregate signature schemes proposed in the past for this purpose are either identity-based or relied on certificateless cryptographic methods. Using these methods, a central authority known as a trusted authority (TA) is responsible for generating and distributing secret keys of every user. However, the key escrow problem is formulated as knowing the secret key generated by the TA. These methods are hampered by key distribution issues, which restrict their applicability in a variety of situations. To address these concerns, this paper presents a certificate-based aggregate signature (CBS-AS) scheme based on hyperelliptic curve cryptography (HECC). The proposed scheme has been shown to be both efficient in terms of computation cost and unforgeable while testing its toughness through formal security analysis.

A Lightweight Certificateless Aggregate Ring Signature Scheme for Privacy-preserving in Smart Grids

There exists a problem of user privacy leakage in the smart grids (SGs) that malicious attackers may intercept or tamper with electricity data and associate the stolen data with real users to commit crimes. Besides, node equipment resources in the SGs are limited. Aiming at the problems above, most of the existing privacy-preserving schemes apply aggregate signature to ensure the integrity of message and improve communication efficiency. However, they cannot realize the anonymity of users to block link attacks, and most of the aggregate signature verification has a high computational cost. Therefore, we propose a certificateless aggregate ring signature (CLARS) scheme based on computational Diffie-Hellman problem and decisional Diffie-Hellman problem. Our scheme is suitable for privacy-preserving in SGs. In this scheme, certificateless cryptosystem is used to avoid key escrow and certificates management problems and ring signature is used to ensure the unconditional anonymity of users. In addition, our scheme is proved to be unforgeability and unconditional anonymity under adaptively chosen message attacks against Type I and Type II adversaries in the random oracle model. Compared with previous certificateless aggregate signature (CLAS) schemes, our CLARS scheme has lower computational cost, which only needs two pairing operations.

Certificateless-Based Anonymous Authentication and Aggregate Signature Scheme for Vehicular Ad Hoc Networks

Development of Internet of Vehicles (IoV) has aroused extensive attention in recent years. The IoV requires an efficient communication mode when the application scenarios are complicated. To reduce the verifying time and cut the length of signature, certificateless aggregate signature (CL-AS) is used to achieve improved performance in resource-constrained environments like vehicular ad hoc networks (VANETs), which is able to make it effective in environments constrained by bandwidth and storage. However, in the real application scenarios, messages should be kept untamed, unleashed, and authentic. In addition, most of the proposed schemes tend to be easy to attack by signers or malicious entities which can be called coalition attack. In this paper, we present an improved certificateless-based authentication and aggregate signature scheme, which can properly solve the coalition attack. Moreover, the proposed scheme not only uses pseudonyms in communications to prevent vehicles from revealing their identity but also achieves considerable efficiency compared with state-of-the-art work, certificateless signature (CLS), and CL-AS schemes. Furthermore, it demonstrates that when focused on the existential forgery on adaptive chosen message attack and coalition attack, the proposed schemes can be proved secure. Also, we show that our scheme exceeds existing certification schemes in both computing and communication costs.